idnits 2.17.00 (12 Aug 2021)
/tmp/idnits62920/draft-ietf-lpwan-overview-03.txt:
Checking boilerplate required by RFC 5378 and the IETF Trust (see
https://trustee.ietf.org/license-info):
----------------------------------------------------------------------------
No issues found here.
Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt:
----------------------------------------------------------------------------
No issues found here.
Checking nits according to https://www.ietf.org/id-info/checklist :
----------------------------------------------------------------------------
No issues found here.
Miscellaneous warnings:
----------------------------------------------------------------------------
== The copyright year in the IETF Trust and authors Copyright Line does not
match the current year
-- The document date (May 25, 2017) is 1822 days in the past. Is this
intentional?
Checking references for intended status: Informational
----------------------------------------------------------------------------
-- Obsolete informational reference (is this intentional?): RFC 2460
(Obsoleted by RFC 8200)
-- Obsolete informational reference (is this intentional?): RFC 3315
(Obsoleted by RFC 8415)
-- Obsolete informational reference (is this intentional?): RFC 5246
(Obsoleted by RFC 8446)
-- Obsolete informational reference (is this intentional?): RFC 6961
(Obsoleted by RFC 8446)
== Outdated reference: A later version (-04) exists of
draft-zuniga-lpwan-sigfox-system-description-02
Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 5 comments (--).
Run idnits with the --verbose option for more detailed information about
the items above.
--------------------------------------------------------------------------------
2 lpwan S. Farrell, Ed.
3 Internet-Draft Trinity College Dublin
4 Intended status: Informational May 25, 2017
5 Expires: November 26, 2017
7 LPWAN Overview
8 draft-ietf-lpwan-overview-03
10 Abstract
12 Low Power Wide Area Networks (LPWAN) are wireless technologies with
13 characteristics such as large coverage areas, low bandwidth, possibly
14 very small packet and application layer data sizes and long battery
15 life operation. This memo is an informational overview of the set of
16 LPWAN technologies being considered in the IETF and of the gaps that
17 exist between the needs of those technologies and the goal of running
18 IP in LPWANs.
20 Status of This Memo
22 This Internet-Draft is submitted in full conformance with the
23 provisions of BCP 78 and BCP 79.
25 Internet-Drafts are working documents of the Internet Engineering
26 Task Force (IETF). Note that other groups may also distribute
27 working documents as Internet-Drafts. The list of current Internet-
28 Drafts is at http://datatracker.ietf.org/drafts/current/.
30 Internet-Drafts are draft documents valid for a maximum of six months
31 and may be updated, replaced, or obsoleted by other documents at any
32 time. It is inappropriate to use Internet-Drafts as reference
33 material or to cite them other than as "work in progress."
35 This Internet-Draft will expire on November 26, 2017.
37 Copyright Notice
39 Copyright (c) 2017 IETF Trust and the persons identified as the
40 document authors. All rights reserved.
42 This document is subject to BCP 78 and the IETF Trust's Legal
43 Provisions Relating to IETF Documents
44 (http://trustee.ietf.org/license-info) in effect on the date of
45 publication of this document. Please review these documents
46 carefully, as they describe your rights and restrictions with respect
47 to this document. Code Components extracted from this document must
48 include Simplified BSD License text as described in Section 4.e of
49 the Trust Legal Provisions and are provided without warranty as
50 described in the Simplified BSD License.
52 Table of Contents
54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
55 2. LPWAN Technologies . . . . . . . . . . . . . . . . . . . . . 3
56 2.1. LoRaWAN . . . . . . . . . . . . . . . . . . . . . . . . . 4
57 2.1.1. Provenance and Documents . . . . . . . . . . . . . . 4
58 2.1.2. Characteristics . . . . . . . . . . . . . . . . . . . 4
59 2.2. Narrowband IoT (NB-IoT) . . . . . . . . . . . . . . . . . 11
60 2.2.1. Provenance and Documents . . . . . . . . . . . . . . 11
61 2.2.2. Characteristics . . . . . . . . . . . . . . . . . . . 11
62 2.3. SIGFOX . . . . . . . . . . . . . . . . . . . . . . . . . 15
63 2.3.1. Provenance and Documents . . . . . . . . . . . . . . 16
64 2.3.2. Characteristics . . . . . . . . . . . . . . . . . . . 16
65 2.4. Wi-SUN Alliance Field Area Network (FAN) . . . . . . . . 20
66 2.4.1. Provenance and Documents . . . . . . . . . . . . . . 20
67 2.4.2. Characteristics . . . . . . . . . . . . . . . . . . . 21
68 3. Generic Terminology . . . . . . . . . . . . . . . . . . . . . 24
69 4. Gap Analysis . . . . . . . . . . . . . . . . . . . . . . . . 25
70 4.1. Naive application of IPv6 . . . . . . . . . . . . . . . . 25
71 4.2. 6LoWPAN . . . . . . . . . . . . . . . . . . . . . . . . . 26
72 4.2.1. Header Compression . . . . . . . . . . . . . . . . . 26
73 4.2.2. Address Autoconfiguration . . . . . . . . . . . . . . 27
74 4.2.3. Fragmentation . . . . . . . . . . . . . . . . . . . . 27
75 4.2.4. Neighbor Discovery . . . . . . . . . . . . . . . . . 28
76 4.3. 6lo . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
77 4.4. 6tisch . . . . . . . . . . . . . . . . . . . . . . . . . 29
78 4.5. RoHC . . . . . . . . . . . . . . . . . . . . . . . . . . 29
79 4.6. ROLL . . . . . . . . . . . . . . . . . . . . . . . . . . 29
80 4.7. CoAP . . . . . . . . . . . . . . . . . . . . . . . . . . 30
81 4.8. Mobility . . . . . . . . . . . . . . . . . . . . . . . . 30
82 4.9. DNS and LPWAN . . . . . . . . . . . . . . . . . . . . . . 30
83 5. Security Considerations . . . . . . . . . . . . . . . . . . . 31
84 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 31
85 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 32
86 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 34
87 9. Informative References . . . . . . . . . . . . . . . . . . . 35
88 Appendix A. Changes . . . . . . . . . . . . . . . . . . . . . . 40
89 A.1. From -00 to -01 . . . . . . . . . . . . . . . . . . . . . 40
90 A.2. From -01 to -02 . . . . . . . . . . . . . . . . . . . . . 40
91 A.3. From -02 to -03 . . . . . . . . . . . . . . . . . . . . . 40
92 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 41
94 1. Introduction
96 This document provides background material and an overview of the
97 technologies being considered in the IETF's Low Power Wide-Area
98 Networking (LPWAN) working group. We also provide a gap analysis
99 between the needs of these technologies and currently available IETF
100 specifications.
102 Most technologies in this space aim for similar goals of supporting
103 large numbers of very low-cost, low-throughput devices with very-low
104 power consumption, so that even battery-powered devices can be
105 deployed for years. LPWAN devices also tend to be constrained in
106 their use of bandwidth, for example with limited frequencies being
107 allowed to be used within limited duty-cycles (usually expressed as a
108 percentage of time per-hour that the device is allowed to transmit.)
109 And as the name implies, coverage of large areas is also a common
110 goal. So, by and large, the different technologies aim for
111 deployment in very similar circumstances.
113 Existing pilot deployments have shown huge potential and created much
114 industrial interest in these technologies. As of today, essentially
115 no LPWAN devices have IP capabilities. Connecting LPWANs to the
116 Internet would provide significant benefits to these networks in
117 terms of interoperability, application deployment, and management,
118 among others. The goal of the IETF LPWAN working group is to, where
119 necessary, adapt IETF-defined protocols, addressing schemes and
120 naming to this particular constrained environment.
122 This document is largely the work of the people listed in Section 7.
124 2. LPWAN Technologies
126 This section provides an overview of the set of LPWAN technologies
127 that are being considered in the LPWAN working group. The text for
128 each was mainly contributed by proponents of each technology.
130 Note that this text is not intended to be normative in any sense, but
131 simply to help the reader in finding the relevant layer 2
132 specifications and in understanding how those integrate with IETF-
133 defined technologies. Similarly, there is no attempt here to set out
134 the pros and cons of the relevant technologies.
136 Note that some of the technology-specific drafts referenced below may
137 have been updated since publication of this document.
139 2.1. LoRaWAN
141 Text here is largely from [I-D.farrell-lpwan-lora-overview]
143 2.1.1. Provenance and Documents
145 LoRaWAN is a wireless technology for long-range low-power low-data-
146 rate applications developed by the LoRa Alliance, a membership
147 consortium. This draft is based on
148 version 1.0.2 [LoRaSpec] of the LoRa specification. Version 1.0,
149 which has also seen some deployment, is available at [LoRaSpec1.0].
151 2.1.2. Characteristics
153 LoRaWAN networks are typically organized in a star-of-stars topology
154 in which gateways relay messages between end-devices and a central
155 "network server" in the backend. Gateways are connected to the
156 network server via IP links while end-devices use single-hop LoRaWAN
157 communication that can be received at one or more gateways. All
158 communication is generally bi-directional, although uplink
159 communication from end-devices to the network server are favored in
160 terms of overall bandwidth availability.
162 Figure 1 shows the entities involved in a LoRaWAN network.
164 +----------+
165 |End-device| * * *
166 +----------+ * +---------+
167 * | Gateway +---+
168 +----------+ * +---------+ | +---------+
169 |End-device| * * * +---+ Network +--- Application
170 +----------+ * | | Server |
171 * +---------+ | +---------+
172 +----------+ * | Gateway +---+
173 |End-device| * * * * +---------+
174 +----------+
175 Key: * LoRaWAN Radio
176 +---+ IP connectivity
178 Figure 1: LoRaWAN architecture
180 o End-device: a LoRa client device, sometimes called a mote.
181 Communicates with gateways.
183 o Gateway: a radio on the infrastructure-side, sometimes called a
184 concentrator or base-station. Communicates with end-devices and,
185 via IP, with a network server.
187 o Network Server: The Network Server (NS) terminates the LoRaWAN MAC
188 layer for the end-devices connected to the network. It is the
189 center of the star topology.
191 o Uplink message: refers to communications from end-device to
192 network server or application via one or more gateways.
194 o Downlink message: refers to communications from network server or
195 application via one gateway to a single end-device or a group of
196 end-devices (considering multicasting).
198 o Application: refers to application layer code both on the end-
199 device and running "behind" the network server. For LoRaWAN,
200 there will generally only be one application running on most end-
201 devices. Interfaces between the network server and application
202 are not further described here.
204 In LoRaWAN networks, end-device transmissions may be received at
205 multiple gateways, so during nominal operation a network server may
206 see multiple instances of the same uplink message from an end-device.
208 The LoRaWAN network infrastructure manages the data rate and RF
209 output power for each end-device individually by means of an adaptive
210 data rate (ADR) scheme. End-devices may transmit on any channel
211 allowed by local regulation at any time.
213 LoRaWAN radios make use of industrial, scientific and medical (ISM)
214 bands, for example, 433MHz and 868MHz within the European Union and
215 915MHz in the Americas.
217 The end-device changes channel in a pseudo-random fashion for every
218 transmission to help make the system more robust to interference and/
219 or to conform to local regulations.
221 Figure 2 below shows that after a transmission slot a Class A device
222 turns on its receiver for two short receive windows that are offset
223 from the end of the transmission window. End-devices can only
224 transmit a subsequent uplink frame after the end of the associated
225 receive windows. When a device joins a LoRaWAN network, there are
226 similar timeouts on parts of that process.
228 |----------------------------| |--------| |--------|
229 | Tx | | Rx | | Rx |
230 |----------------------------| |--------| |--------|
231 |---------|
232 Rx delay 1
233 |------------------------|
234 Rx delay 2
236 Figure 2: LoRaWAN Class A transmission and reception window
238 Given the different regional requirements the detailed specification
239 for the LoRaWAN physical layer (taking up more than 30 pages of the
240 specification) is not reproduced here. Instead and mainly to
241 illustrate the kinds of issue encountered, in Table 1 we present some
242 of the default settings for one ISM band (without fully explaining
243 those here) and in Table 2 we describe maxima and minima for some
244 parameters of interest to those defining ways to use IETF protocols
245 over the LoRaWAN MAC layer.
247 +------------------------+------------------------------------------+
248 | Parameters | Default Value |
249 +------------------------+------------------------------------------+
250 | Rx delay 1 | 1 s |
251 | | |
252 | Rx delay 2 | 2 s (must be RECEIVE_DELAY1 + 1s) |
253 | | |
254 | join delay 1 | 5 s |
255 | | |
256 | join delay 2 | 6 s |
257 | | |
258 | 868MHz Default | 3 (868.1,868.2,868.3), data rate: 0.3-5 |
259 | channels | kbps |
260 +------------------------+------------------------------------------+
262 Table 1: Default settings for EU868MHz band
264 +-----------------------------------------------+--------+----------+
265 | Parameter/Notes | Min | Max |
266 +-----------------------------------------------+--------+----------+
267 | Duty Cycle: some but not all ISM bands impose | 1% | no-limit |
268 | a limit in terms of how often an end-device | | |
269 | can transmit. In some cases LoRaWAN is more | | |
270 | stringent in an attempt to avoid congestion. | | |
271 | | | |
272 | EU 868MHz band data rate/frame-size | 250 | 50000 |
273 | | bits/s | bits/s : |
274 | | : 59 | 250 |
275 | | octets | octets |
276 | | | |
277 | US 915MHz band data rate/frame-size | 980 | 21900 |
278 | | bits/s | bits/s : |
279 | | : 19 | 250 |
280 | | octets | octets |
281 +-----------------------------------------------+--------+----------+
283 Table 2: Minima and Maxima for various LoRaWAN Parameters
285 Note that in the case of the smallest frame size (19 octets), 8
286 octets are required for LoRa MAC layer headers leaving only 11 octets
287 for payload (including MAC layer options). However, those settings
288 do not apply for the join procedure - end-devices are required to use
289 a channel and data rate that can send the 23-byte Join-request
290 message for the join procedure.
292 Uplink and downlink higher layer data is carried in a MACPayload.
293 There is a concept of "ports" (an optional 8-bit value) to handle
294 different applications on an end-device. Port zero is reserved for
295 LoRaWAN specific messaging, such as the configuration of the end
296 device's network parameters (available channels, data rates, ADR
297 parameters, RX1/2 delay, etc.).
299 In addition to carrying higher layer PDUs there are Join-Request and
300 Join-Response (aka Join-Accept) messages for handling network access.
301 And so-called "MAC commands" (see below) up to 15 bytes long can be
302 piggybacked in an options field ("FOpts").
304 There are a number of MAC commands for link and device status
305 checking, ADR and duty-cycle negotiation, managing the RX windows and
306 radio channel settings. For example, the link check response message
307 allows the network server (in response to a request from an end-
308 device) to inform an end-device about the signal attenuation seen
309 most recently at a gateway, and to also tell the end-device how many
310 gateways received the corresponding link request MAC command.
312 Some MAC commands are initiated by the network server. For example,
313 one command allows the network server to ask an end-device to reduce
314 its duty-cycle to only use a proportion of the maximum allowed in a
315 region. Another allows the network server to query the end-device's
316 power status with the response from the end-device specifying whether
317 it has an external power source or is battery powered (in which case
318 a relative battery level is also sent to the network server).
320 A LoRaWAN network has a short network identifier ("NwkID") which is a
321 seven-bit value. A private network (common for LoRaWAN) can use the
322 value zero. If a network wishes to support "foreign" end-devices
323 then the NwkID needs to be registered with the LoRA Alliance, in
324 which case the NwkID is the seven least significant bits of a
325 registered 24-bit NetID. (Note however, that the methods for
326 "roaming" are defined in the upcoming LoRaWAN 1.1 specification.)
328 In order to operate nominally on a LoRaWAN network, a device needs a
329 32-bit device address, which is the catenation of the NwkID and a
330 25-bit device-specific network address that is assigned when the
331 device "joins" the network (see below for the join procedure) or that
332 is pre-provisioned into the device.
334 End-devices are assumed to work with one or a quite limited number of
335 applications, identified by a 64-bit AppEUI, which is assumed to be a
336 registered IEEE EUI64 value. In addition, a device needs to have two
337 symmetric session keys, one for protecting network artifacts
338 (port=0), the NwkSKey, and another for protecting application layer
339 traffic, the AppSKey. Both keys are used for 128-bit AES
340 cryptographic operations. So, one option is for an end-device to
341 have all of the above, plus channel information, somehow
342 (pre-)provisioned, in which case the end-device can simply start
343 transmitting. This is achievable in many cases via out-of-band means
344 given the nature of LoRaWAN networks. Table 3 summarizes these
345 values.
347 +---------+---------------------------------------------------------+
348 | Value | Description |
349 +---------+---------------------------------------------------------+
350 | DevAddr | DevAddr (32-bits) = NwkId (7-bits) + device-specific |
351 | | network address (25 bits) |
352 | | |
353 | AppEUI | IEEE EUI64 naming the application |
354 | | |
355 | NwkSKey | 128-bit network session key for use with AES |
356 | | |
357 | AppSKey | 128-bit application session key for use with AES |
358 +---------+---------------------------------------------------------+
360 Table 3: Values required for nominal operation
362 As an alternative, end-devices can use the LoRaWAN join procedure in
363 order to setup some of these values and dynamically gain access to
364 the network. To use the join procedure, an end-device must still
365 know the AppEUI, and in addition, a different (long-term) symmetric
366 key that is bound to the AppEUI - this is the application key
367 (AppKey), and is distinct from the application session key (AppSKey).
368 The AppKey is required to be specific to the device, that is, each
369 end-device should have a different AppKey value. And finally, the
370 end-device also needs a long-term identifier for itself,
371 syntactically also an EUI-64, and known as the device EUI or DevEUI.
372 Table 4 summarizes these values.
374 +---------+----------------------------------------------------+
375 | Value | Description |
376 +---------+----------------------------------------------------+
377 | DevEUI | IEEE EUI64 naming the device |
378 | | |
379 | AppEUI | IEEE EUI64 naming the application |
380 | | |
381 | AppKey | 128-bit long term application key for use with AES |
382 +---------+----------------------------------------------------+
384 Table 4: Values required for join procedure
386 The join procedure involves a special exchange where the end-device
387 asserts the AppEUI and DevEUI (integrity protected with the long-term
388 AppKey, but not encrypted) in a Join-request uplink message. This is
389 then routed to the network server which interacts with an entity that
390 knows that AppKey to verify the Join-request. All going well, a
391 Join-accept downlink message is returned from the network server to
392 the end-device that specifies the 24-bit NetID, 32-bit DevAddr and
393 channel information and from which the AppSKey and NwkSKey can be
394 derived based on knowledge of the AppKey. This provides the end-
395 device with all the values listed in Table 3.
397 All payloads are encrypted and have data integrity. MAC commands,
398 when sent as a payload (port zero), are therefore protected. MAC
399 commands piggy-backed as frame options ("FOpts") are however sent in
400 clear. Any MAC commands sent as frame options and not only as
401 payload, are visible to a passive attacker but are not malleable for
402 an active attacker due to the use of the Message Integrity Check
403 (MIC) described below..
405 For LoRaWAN version 1.0.x, the NWkSkey session key is used to provide
406 data integrity between the end-device and the network server. The
407 AppSKey is used to provide data confidentiality between the end-
408 device and network server, or to the application "behind" the network
409 server, depending on the implementation of the network.
411 All MAC layer messages have an outer 32-bit MIC calculated using AES-
412 CMAC calculated over the ciphertext payload and other headers and
413 using the NwkSkey. Payloads are encrypted using AES-128, with a
414 counter-mode derived from IEEE 802.15.4 using the AppSKey. Gateways
415 are not expected to be provided with the AppSKey or NwkSKey, all of
416 the infrastructure-side cryptography happens in (or "behind") the
417 network server. When session keys are derived from the AppKey as a
418 result of the join procedure the Join-accept message payload is
419 specially handled.
421 The long-term AppKey is directly used to protect the Join-accept
422 message content, but the function used is not an AES-encrypt
423 operation, but rather an AES-decrypt operation. The justification is
424 that this means that the end-device only needs to implement the AES-
425 encrypt operation. (The counter mode variant used for payload
426 decryption means the end-device doesn't need an AES-decrypt
427 primitive.)
429 The Join-accept plaintext is always less than 16 bytes long, so
430 electronic code book (ECB) mode is used for protecting Join-accept
431 messages. The Join-accept contains an AppNonce (a 24 bit value) that
432 is recovered on the end-device along with the other Join-accept
433 content (e.g. DevAddr) using the AEs-encrypt operation. Once the
434 Join-accept payload is available to the end-device the session keys
435 are derived from the AppKey, AppNonce and other values, again using
436 an ECB mode AES-encrypt operation, with the plaintext input being a
437 maximum of 16 octets.
439 2.2. Narrowband IoT (NB-IoT)
441 Text here is largely from [I-D.ratilainen-lpwan-nb-iot]
443 2.2.1. Provenance and Documents
445 Narrowband Internet of Things (NB-IoT) is developed and standardized
446 by 3GPP. The standardization of NB-IoT was finalized with 3GPP
447 Release 13 in June 2016, and further enhancements for NB-IoT are
448 specified in 3GPP Release 14 in 2017, for example in the form of
449 multicast support. Further features and improvements will be
450 developed in the following releases, but NB-IoT has been ready to be
451 deployed since 2016, and is rather simple to deploy especially in the
452 existing LTE networks with a software upgrade in the operator's base
453 stations. For more information of what has been specified for NB-
454 IoT, 3GPP specification 36.300 [TGPP36300] provides an overview and
455 overall description of the E-UTRAN radio interface protocol
456 architecture, while specifications 36.321 [TGPP36321], 36.322
457 [TGPP36322], 36.323 [TGPP36323] and 36.331 [TGPP36331] give more
458 detailed description of MAC, RLC, PDCP and RRC protocol layers,
459 respectively. Note that the description below assumes familiarity
460 with numerous 3GPP terms.
462 2.2.2. Characteristics
464 Specific targets for NB-IoT include: Less than US$5 module cost,
465 extended coverage of 164 dB maximum coupling loss, battery life of
466 over 10 years, ~55000 devices per cell and uplink reporting latency
467 of less than 10 seconds.
469 NB-IoT supports Half Duplex FDD operation mode with 60 kbps peak rate
470 in uplink and 30 kbps peak rate in downlink, and a maximum
471 transmission unit (MTU) size of 1600 bytes limited by PDCP layer (see
472 Figure 4 for the protocol structure), which is the highest layer in
473 the user plane, as explained later. Any packet size up to the said
474 MTU size can be passed to the NB-IoT stack from higher layers,
475 segmentation of the packet is performed in the RLC layer, which can
476 segment the data to transmission blocks with size as small as 16
477 bits. As the name suggests, NB-IoT uses narrowbands with the
478 bandwidth of 180 kHz in both downlink and uplink. The multiple
479 access scheme used in the downlink is OFDMA with 15 kHz sub-carrier
480 spacing. In uplink SC-FDMA single tone with either 15kHz or 3.75 kHz
481 tone spacing is used, or optionally multi-tone SC- FDMA can be used
482 with 15 kHz tone spacing.
484 NB-IoT can be deployed in three ways. In-band deployment means that
485 the narrowband is deployed inside the LTE band and radio resources
486 are flexibly shared between NB-IoT and normal LTE carrier. In Guard-
487 band deployment the narrowband uses the unused resource blocks
488 between two adjacent LTE carriers. Standalone deployment is also
489 supported, where the narrowband can be located alone in dedicated
490 spectrum, which makes it possible for example to reframe a GSM
491 carrier at 850/900 MHz for NB-IoT. All three deployment modes are
492 used in licensed frequency bands. The maximum transmission power is
493 either 20 or 23 dBm for uplink transmissions, while for downlink
494 transmission the eNodeB may use higher transmission power, up to 46
495 dBm depending on the deployment.
497 A maximum coupling loss (MCL) target for NB-IoT coverage enhancements
498 defined by 3GPP is 164 dB. With this MCL, the performance of NB-IoT
499 in downlink varies between 200 bps and 2-3 kbps, depending on the
500 deployment mode. Stand-alone operation may achieve the highest data
501 rates, up to few kbps, while in-band and guard-band operations may
502 reach several hundreds of bps. NB-IoT may even operate with MCL
503 higher than 170 dB with very low bit rates.
505 For signaling optimization, two options are introduced in addition to
506 legacy LTE RRC connection setup; mandatory Data-over-NAS (Control
507 Plane optimization, solution 2 in [TGPP23720]) and optional RRC
508 Suspend/Resume (User Plane optimization, solution 18 in [TGPP23720]).
509 In the control plane optimization the data is sent over Non-Access
510 Stratum, directly to/from Mobility Management Entity (MME) (see
511 Figure 3 for the network architecture) in the core network to the UE
512 without interaction from the base station. This means there are no
513 Access Stratum security or header compression provided by the PDCP
514 layer in the eNodeB, as the Access Stratum is bypassed, and only
515 limited RRC procedures. RoHC based header compression may still
516 optionally be provided and terminated in MME.
518 The RRC Suspend/Resume procedures reduce the signaling overhead
519 required for UE state transition from RRC Idle to RRC Connected mode
520 compared to legacy LTE operation in order to have quicker user plane
521 transaction with the network and return to RRC Idle mode faster.
523 In order to prolong device battery life, both power-saving mode (PSM)
524 and extended DRX (eDRX) are available to NB-IoT. With eDRX the RRC
525 Connected mode DRX cycle is up to 10.24 seconds and in RRC Idle the
526 eDRX cycle can be up to 3 hours. In PSM the device is in a deep
527 sleep state and only wakes up for uplink reporting, after which there
528 is a window, configured by the network, during which the device
529 receiver is open for downlink connectivity, of for periodical "keep-
530 alive" signaling (PSM uses periodic TAU signaling with additional
531 reception window for downlink reachability).
533 Since NB-IoT operates in licensed spectrum, it has no channel access
534 restrictions allowing up to a 100% duty-cycle.
536 3GPP access security is specified in [TGPP33203].
538 +--+
539 |UE| \ +------+ +------+
540 +--+ \ | MME |------| HSS |
541 \ / +------+ +------+
542 +--+ \+-----+ / |
543 |UE| ----| eNB |- |
544 +--+ /+-----+ \ |
545 / \ +--------+
546 / \| | +------+ Service PDN
547 +--+ / | S-GW |----| P-GW |---- e.g. Internet
548 |UE| | | +------+
549 +--+ +--------+
551 Figure 3: 3GPP network architecture
553 Figure 3 shows the 3GPP network architecture, which applies to NB-
554 IoT. Mobility Management Entity (MME) is responsible for handling
555 the mobility of the UE. MME tasks include tracking and paging UEs,
556 session management, choosing the Serving gateway for the UE during
557 initial attachment and authenticating the user. At MME, the Non-
558 Access Stratum (NAS) signaling from the UE is terminated.
560 Serving Gateway (S-GW) routes and forwards the user data packets
561 through the access network and acts as a mobility anchor for UEs
562 during handover between base stations known as eNodeBs and also
563 during handovers between NB-IoT and other 3GPP technologies.
565 Packet Data Node Gateway (P-GW) works as an interface between 3GPP
566 network and external networks.
568 The Home Subscriber Server (HSS) contains user-related and
569 subscription- related information. It is a database, which performs
570 mobility management, session establishment support, user
571 authentication and access authorization.
573 E-UTRAN consists of components of a single type, eNodeB. eNodeB is a
574 base station, which controls the UEs in one or several cells.
576 The illustration of 3GPP radio protocol architecture can be seen from
577 Figure 4.
579 +---------+ +---------+
580 | NAS |----|-----------------------------|----| NAS |
581 +---------+ | +---------+---------+ | +---------+
582 | RRC |----|----| RRC | S1-AP |----|----| S1-AP |
583 +---------+ | +---------+---------+ | +---------+
584 | PDCP |----|----| PDCP | SCTP |----|----| SCTP |
585 +---------+ | +---------+---------+ | +---------+
586 | RLC |----|----| RLC | IP |----|----| IP |
587 +---------+ | +---------+---------+ | +---------+
588 | MAC |----|----| MAC | L2 |----|----| L2 |
589 +---------+ | +---------+---------+ | +---------+
590 | PHY |----|----| PHY | PHY |----|----| PHY |
591 +---------+ +---------+---------+ +---------+
592 LTE-Uu S1-MME
593 UE eNodeB MME
595 Figure 4: 3GPP radio protocol architecture for control plane
597 Control plane protocol stack
599 The radio protocol architecture of NB-IoT (and LTE) is separated into
600 control plane and user plane. The control plane consists of
601 protocols which control the radio access bearers and the connection
602 between the UE and the network. The highest layer of control plane
603 is called Non-Access Stratum (NAS), which conveys the radio signaling
604 between the UE and the EPC, passing transparently through the radio
605 network. It is responsible for authentication, security control,
606 mobility management and bearer management.
608 Access Stratum (AS) is the functional layer below NAS, and in control
609 plane it consists of Radio Resource Control protocol (RRC)
610 [TGPP36331], which handles connection establishment and release
611 functions, broadcast of system information, radio bearer
612 establishment, reconfiguration and release. RRC configures the user
613 and control planes according to the network status. There exists two
614 RRC states, RRC_Idle or RRC_Connected, and RRC entity controls the
615 switching between these states. In RRC_Idle, the network knows that
616 the UE is present in the network and the UE can be reached in case of
617 incoming call/downlink data. In this state, the UE monitors paging,
618 performs cell measurements and cell selection and acquires system
619 information. Also the UE can receive broadcast and multicast data,
620 but it is not expected to transmit or receive unicast data. In
621 RRC_Connected the UE has a connection to the eNodeB, the network
622 knows the UE location on the cell level and the UE may receive and
623 transmit unicast data. An RRC connection is established when the UE
624 is expected to be active in the network, to transmit or receive data.
625 The RRC connection is released, switching back to RRC_Idle, when
626 there is no more traffic in order to preserve UE battery life and
627 radio resources. However, a new feature was introduced for NB-IoT,
628 as mentioned earlier, which allows data to be transmitted from the
629 MME directly to the UE transparently to the eNodeB, thus bypassing AS
630 functions.
632 Packet Data Convergence Protocol's (PDCP) [TGPP36323] main services
633 in control plane are transfer of control plane data, ciphering and
634 integrity protection.
636 Radio Link Control protocol (RLC) [TGPP36322] performs transfer of
637 upper layer PDUs and optionally error correction with Automatic
638 Repeat reQuest (ARQ), concatenation, segmentation, and reassembly of
639 RLC SDUs, in-sequence delivery of upper layer PDUs, duplicate
640 detection, RLC SDU discard, RLC-re-establishment and protocol error
641 detection and recovery.
643 Medium Access Control protocol (MAC) [TGPP36321] provides mapping
644 between logical channels and transport channels, multiplexing of MAC
645 SDUs, scheduling information reporting, error correction with HARQ,
646 priority handling and transport format selection.
648 Physical layer [TGPP36201] provides data transport services to higher
649 layers. These include error detection and indication to higher
650 layers, FEC encoding, HARQ soft-combining. Rate matching and mapping
651 of the transport channels onto physical channels, power weighting and
652 modulation of physical channels, frequency and time synchronization
653 and radio characteristics measurements.
655 User plane protocol stack
657 User plane is responsible for transferring the user data through the
658 Access Stratum. It interfaces with IP and the highest layer of user
659 plane is PDCP, which in user plane performs header compression using
660 Robust Header Compression (RoHC), transfer of user plane data between
661 eNodeB and UE, ciphering and integrity protection. Similar to
662 control plane, lower layers in user plane include RLC, MAC and
663 physical layer performing the same tasks as in control plane.
665 2.3. SIGFOX
667 Text here is largely from
668 [I-D.zuniga-lpwan-sigfox-system-description] which may have been
669 updated since this was published.
671 2.3.1. Provenance and Documents
673 The SIGFOX LPWAN is in line with the terminology and specifications
674 being defined by the ETSI ERM TG28 Low Throughput Networks (LTN)
675 group [etsi_ltn]. As of today, SIGFOX's network has been fully
676 deployed in 6 countries, with ongoing deployments on 18 other
677 countries, in total a geography containing 397M people.
679 2.3.2. Characteristics
681 SIGFOX LPWAN autonomous battery-operated devices send only a few
682 bytes per day, week or month, in principle allowing them to remain on
683 a single battery for up to 10-15 years. The capacity of a SIGFOX
684 base station mainly depends on the number of messages generated by
685 the devices, and not on the number of devices. The battery life of
686 devices also depends on the number of messages generated by the
687 device, but it is important to keep in mind that these devices are
688 designed to last several years, some of them even buried underground.
689 The coverage of the cell also depends on the link budget and on the
690 type of deployment (urban, rural, etc.), which can vary from sending
691 less than one message per device per day to dozens of messages per
692 device per day.
694 The radio interface is compliant with the following regulations:
696 Spectrum allocation in the USA [fcc_ref]
698 Spectrum allocation in Europe [etsi_ref]
700 Spectrum allocation in Japan [arib_ref]
702 The SIGFOX LTN radio interface is also compliant with the local
703 regulations of the following countries: Australia, Brazil, Canada,
704 Kenya, Lebanon, Mauritius, Mexico, New Zealand, Oman, Peru,
705 Singapore, South Africa, South Korea, and Thailand.
707 The radio interface is based on Ultra Narrow Band (UNB)
708 communications, which allow an increased transmission range by
709 spending a limited amount of energy at the device. Moreover, UNB
710 allows a large number of devices to coexist in a given cell without
711 significantly increasing the spectrum interference.
713 Both uplink and downlink communications are possible with the UNB
714 solution. Due to spectrum optimizations, different uplink and
715 downlink frames and time synchronization methods are needed.
717 The main radio characteristics of the UNB uplink transmission are:
719 o Channelization mask: 100 Hz (600 Hz in the USA)
721 o Uplink baud rate: 100 baud (600 baud in the USA)
723 o Modulation scheme: DBPSK
725 o Uplink transmission power: compliant with local regulation
727 o Link budget: 155 dB (or better)
729 o Central frequency accuracy: not relevant, provided there is no
730 significant frequency drift within an uplink packet
732 In Europe, the UNB uplink frequency band is limited to 868,00 to
733 868,60 MHz, with a maximum output power of 25 mW and a maximum mean
734 transmission time of 1%.
736 The format of the uplink frame is the following:
738 +--------+--------+--------+------------------+-------------+-----+
739 |Preamble| Frame | Dev ID | Payload |Msg Auth Code| FCS |
740 | | Sync | | | | |
741 +--------+--------+--------+------------------+-------------+-----+
743 Figure 5: Uplink Frame Format
745 The uplink frame is composed of the following fields:
747 o Preamble: 19 bits
749 o Frame sync and header: 29 bits
751 o Device ID: 32 bits
753 o Payload: 0-96 bits
755 o Authentication: 16-40 bits
757 o Frame check sequence: 16 bits (CRC)
759 The main radio characteristics of the UNB downlink transmission are:
761 o Channelization mask: 1.5 kHz
763 o Downlink baud rate: 600 baud
765 o Modulation scheme: GFSK
766 o Downlink transmission power: 500 mW (4W in the USA)
768 o Link budget: 153 dB (or better)
770 o Central frequency accuracy: Centre frequency of downlink
771 transmission are set by the network according to the corresponding
772 uplink transmission.
774 In Europe, the UNB downlink frequency band is limited to 869,40 to
775 869,65 MHz, with a maximum output power of 500 mW with 10% duty
776 cycle.
778 The format of the downlink frame is the following:
780 +------------+-----+---------+------------------+-------------+-----+
781 | Preamble |Frame| ECC | Payload |Msg Auth Code| FCS |
782 | |Sync | | | | |
783 +------------+-----+---------+------------------+-------------+-----+
785 Figure 6: Downlink Frame Format
787 The downlink frame is composed of the following fields:
789 o Preamble: 91 bits
791 o Frame sync and header: 13 bits
793 o Error Correcting Code (ECC): 32 bits
795 o Payload: 0-64 bits
797 o Authentication: 16 bits
799 o Frame check sequence: 8 bits (CRC)
801 The radio interface is optimized for uplink transmissions, which are
802 asynchronous. Downlink communications are achieved by querying the
803 network for existing data from the device.
805 A device willing to receive downlink messages opens a fixed window
806 for reception after sending an uplink transmission. The delay and
807 duration of this window have fixed values. The LTN transmits the
808 downlink message for a given device during the reception window. The
809 LTN selects the base station (BS) for transmitting the corresponding
810 downlink message.
812 Uplink and downlink transmissions are unbalanced due to the
813 regulatory constraints on the ISM bands. Under the strictest
814 regulations, the system can allow a maximum of 140 uplink messages
815 and 4 downlink messages per device per day. These restrictions can
816 be slightly relaxed depending on system conditions and the specific
817 regulatory domain of operation.
819 +--+
820 |EP| * +------+
821 +--+ * | RA |
822 * +------+
823 +--+ * |
824 |EP| * * * * |
825 +--+ * +----+ |
826 * | BS | \ +--------+
827 +--+ * +----+ \ | |
828 DA -----|EP| * * * | SC |----- NA
829 +--+ * / | |
830 * +----+ / +--------+
831 +--+ * | BS |/
832 |EP| * * * * +----+
833 +--+ *
834 *
835 +--+ *
836 |EP| * *
837 +--+
839 Figure 7: SIGFOX architecture
841 Figure 7 depicts the different elements of the SIGFOX architecture.
843 SIGFOX has a "one-contract one-network" model allowing devices to
844 connect in any country, without any notion of roaming.
846 The architecture consists of a single core network, which allows
847 global connectivity with minimal impact on the end device and radio
848 access network. The core network elements are the Service Center
849 (SC) and the Registration Authority (RA). The SC is in charge of the
850 data connectivity between the Base Station (BS) and the Internet, as
851 well as the control and management of the BSs and End Points. The RA
852 is in charge of the End Point network access authorization.
854 The radio access network is comprised of several BSs connected
855 directly to the SC. Each BS performs complex L1/L2 functions,
856 leaving some L2 and L3 functionalities to the SC.
858 The devices or End Points (EPs) are the objects that communicate
859 application data between local device applications (DAs) and network
860 applications (NAs).
862 EPs (or devices) can be static or nomadic, as they associate with the
863 SC and they do not attach to a specific BS. Hence, they can
864 communicate with the SC through one or many BSs.
866 Due to constraints in the complexity of the EP, it is assumed that
867 EPs host only one or very few device applications, which communicate
868 to one single network application at a time.
870 The radio protocol provides mechanisms to authenticate and ensure
871 integrity of the message. This is achieved by using a unique device
872 ID and a message authentication code, which allow ensuring that the
873 message has been generated and sent by the device with the ID claimed
874 in the message.
876 Security keys are independent for each device. These keys are
877 associated with the device ID and they are pre-provisioned.
878 Application data can be encrypted by the application provider.
880 2.4. Wi-SUN Alliance Field Area Network (FAN)
882 Text here is via personal communication from Bob Heile
883 (bheile@ieee.org) and was authored by Bob and Sum Chin Sean. Duffy
884 (paduffy@cisco.com) also provided additional comments/input on this
885 section.
887 2.4.1. Provenance and Documents
889 The Wi-SUN Alliance is an industry alliance
890 for smart city, smart grid, smart utility, and a broad set of general
891 IoT applications. The Wi-SUN Alliance Field Area Network (FAN)
892 profile is open standards based (primarily on IETF and IEEE802
893 standards) and was developed to address applications like smart
894 municipality/city infrastructure monitoring and management, electric
895 vehicle (EV) infrastructure, advanced metering infrastructure (AMI),
896 distribution automation (DA), supervisory control and data
897 acquisition (SCADA) protection/management, distributed generation
898 monitoring and management, and many more IoT applications.
899 Additionally, the Alliance has created a certification program to
900 promote global multi-vendor interoperability.
902 The FAN profile is currently being specified within ANSI/TIA as an
903 extension of work previously done on Smart Utility Networks.
904 [ANSI-4957-000]. Updates to those specifications intended to be
905 published in 2017 will contain details of the FAN profile. A current
906 snapshot of the work to produce that profile is presented in
907 [wisun-pressie1] [wisun-pressie2] .
909 2.4.2. Characteristics
911 The FAN profile is an IPv6 frequency hopping wireless mesh network
912 with support for enterprise level security. The frequency hopping
913 wireless mesh topology aims to offer superior network robustness,
914 reliability due to high redundancy, good scalability due to the
915 flexible mesh configuration and good resilience to interference.
916 Very low power modes are in development permitting long term battery
917 operation of network nodes.
919 The core architecture of Wi-SUN FAN is a mesh network. A FAN
920 contains one or more networks. Within a network, nodes assume one of
921 three operational roles. First, each network contains a Border
922 Router providing Wide Area Network (WAN) connectivity to the network.
923 The Border Router maintains source routing tables for all nodes
924 within its network, provides node authentication and key management
925 services, and disseminates network-wide information such as broadcast
926 schedules. Secondly, Router nodes, which provide upward and downward
927 packet forwarding (within a network). A Router also provides
928 services for relaying security and address management protocols.
929 Lastly, Leaf nodes provide minimum capabilities: discovering and
930 joining a network, send/receive IPv6 packets, etc. A low power
931 network may contain a mesh topology with Routers at the edges that
932 construct a star topology with Leaf nodes.
934 The FAN profile is based on various open standards developed by the
935 IETF (including [RFC0768], [RFC2460], [RFC4443] and [RFC6282]),
936 IEEE802 (including [IEEE-802-15-4] and [IEEE-802-15-9]) and ANSI/TIA
937 [ANSI-4957-210] for low power and lossy networks.
939 The FAN profile specification provides an application-independent
940 IPv6-based transport service for both connectionless (i.e. UDP) and
941 connection-oriented (i.e. TCP) services. There are two possible
942 methods for establishing the IPv6 packet routing: mandatory Routing
943 Protocol for Low-Power and Lossy Networks (RPL) at the Network layer
944 or optional Multi-Hop Delivery Service (MHDS) at the Data Link layer.
945 Table 5 provides an overview of the FAN network stack.
947 The Transport service is based on User Datagram Protocol (UDP)
948 defined in RFC768 or Transmission Control Protocol (TCP) defined in
949 RFC793.
951 The Network service is provided by IPv6 defined in RFC2460 with
952 6LoWPAN adaptation as defined in RC4944 and RFC6282. Additionally,
953 ICMPv6, as defined in RFC4443, is used for control plane in
954 information exchange.
956 The Data Link service provides both control/management of the
957 Physical layer and data transfer/management services to the Network
958 layer. These services are divided into Media Access Control (MAC)
959 and Logical Link Control (LLC) sub-layers. The LLC sub-layer
960 provides a protocol dispatch service which supports 6LoWPAN and an
961 optional MAC sub-layer mesh service. The MAC sub-layer is
962 constructed using data structures defined in IEEE802.15.4-2015.
963 Multiple modes of frequency hopping are defined. The entire MAC
964 payload is encapsulated in an IEEE802.15.9 Information Element to
965 enable LLC protocol dispatch between upper layer 6LoWPAN processing,
966 MAC sublayer mesh processing, etc. These areas will be expanded once
967 IEEE802.15.12 is completed
969 The PHY service is derived from a sub-set of the SUN FSK
970 specification in IEEE802.15.4-2015. The 2-FSK modulation schemes,
971 with channel spacing range from 200 to 600 kHz, are defined to
972 provide data rates from 50 to 300 kbps, with Forward Error Coding
973 (FEC) as an optional feature. Towards enabling ultra-low-power
974 applications, the PHY layer design is also extendable to low energy
975 and critical infrastructure monitoring networks.
977 +------------------------------+------------------------------------+
978 | Layer | Description |
979 +------------------------------+------------------------------------+
980 | IPv6 protocol suite | TCP/UDP |
981 | | |
982 | | 6LoWPAN Adaptation + Header |
983 | | Compression |
984 | | |
985 | | DHCPv6 for IP address management. |
986 | | |
987 | | Routing using RPL. |
988 | | |
989 | | ICMPv6. |
990 | | |
991 | | Unicast and Multicast forwarding. |
992 | | |
993 | MAC based on IEEE 802.15.4e | Frequency hopping |
994 | + IE extensions | |
995 | | |
996 | | Discovery and Join |
997 | | |
998 | | Protocol Dispatch (IEEE 802.15.9) |
999 | | |
1000 | | Several Frame Exchange patterns |
1001 | | |
1002 | | Optional Mesh Under routing (ANSI |
1003 | | 4957.210). |
1004 | | |
1005 | PHY based on 802.15.4g | Various data rates and regions |
1006 | | |
1007 | Security | 802.1X/EAP-TLS/PKI |
1008 | | Authentication. |
1009 | | |
1010 | | 802.11i Group Key Management |
1011 | | |
1012 | | Optional ETSI-TS-102-887-2 Node 2 |
1013 | | Node Key Management |
1014 +------------------------------+------------------------------------+
1016 Table 5: Wi-SUN Stack Overview
1018 The FAN security supports Data Link layer network access control,
1019 mutual authentication, and establishment of a secure pairwise link
1020 between a FAN node and its Border Router, which is implemented with
1021 an adaptation of IEEE802.1X and EAP-TLS as described in [RFC5216]
1022 using secure device identity as described in IEEE802.1AR.
1023 Certificate formats are based upon [RFC5280]. A secure group link
1024 between a Border Router and a set of FAN nodes is established using
1025 an adaptation of the IEEE802.11 Four-Way Handshake. A set of 4 group
1026 keys are maintained within the network, one of which is the current
1027 transmit key. Secure node to node links are supported between one-
1028 hop FAN neighbors using an adaptation of ETSI-TS-102-887-2. FAN
1029 nodes implement Frame Security as specified in IEEE802.15.4-2015.
1031 3. Generic Terminology
1033 LPWAN technologies, such as those discussed above, have similar
1034 architectures but different terminology. We can identify different
1035 types of entities in a typical LPWAN network:
1037 o End-Devices are the devices or the "things" (e.g. sensors,
1038 actuators, etc.), they are named differently in each technology
1039 (End Device, User Equipment or End Point). There can be a high
1040 density of end devices per radio gateway.
1042 o The Radio Gateway, which is the end point of the constrained link.
1043 It is known as: Gateway, Evolved Node B or Base station.
1045 o The Network Gateway or Router is the interconnection node between
1046 the Radio Gateway and the Internet. It is known as: Network
1047 Server, Serving GW or Service Center.
1049 o LPWAN-AAA Server, which controls the user authentication, the
1050 applications. It is known as: Join-Server, Home Subscriber Server
1051 or Registration Authority. (We use the term LPWAN-AAA server
1052 because we're not assuming that this entity speaks RADIUS or
1053 Diameter as many/most AAA servers do, but equally we don't want to
1054 rule that out, as the functionality will be similar.
1056 o At last we have the Application Server, known also as Packet Data
1057 Node Gateway or Network Application.
1059 +---------------------------------------------------------------------+
1060 | Function/ | | | | |
1061 | Technology | LORAWAN | NB-IOT | SIGFOX | IETF |
1062 +--------------+-----------+------------+-------------+---------------+
1063 | Sensor, | | | | |
1064 | Actuator, | End | User | End | Device |
1065 |device, object| Device | Equipment | Point | (Dev) |
1066 +--------------+-----------+------------+-------------+---------------+
1067 | Transceiver | | Evolved | Base | RADIO |
1068 | Antenna | Gateway | Node B | Station | GATEWAY |
1069 +--------------+-----------+------------+-------------+---------------+
1070 | Server | Network | PDN GW/ | Service |Network Gateway|
1071 | | Server | SCEF | Center | (NGW) |
1072 +--------------+-----------+------------+-------------+---------------+
1073 | Security | Join | Home |Registration | LPWAN- |
1074 | Server | Server | Subscriber | Authority | AAA |
1075 | | | Server | | SERVER |
1076 +--------------+-----------+------------+-------------+---------------+
1077 | Application |Application| Application| Network | APPLICATION |
1078 | | Server | Server | Application | (App) |
1079 +---------------------------------------------------------------------+
1081 Figure 8: LPWAN Architecture Terminology
1083 +------+
1084 () () () | |LPWAN-|
1085 () () () () / \ +---------+ | AAA |
1086 () () () () () () / \========| /\ |====|Server| +-----------+
1087 () () () | | <--|--> | +------+ |APPLICATION|
1088 () () () () / \============| v |==============| (App) |
1089 () () () / \ +---------+ +-----------+
1090 Dev Radio Gateways NGW
1092 Figure 9: LPWAN Architecture
1094 In addition to the names of entities, LPWANs are also subject to
1095 possibly regional frequency band regulations. Those may include
1096 restrictions on the duty-cycle, for example requiring that hosts only
1097 transmit for a certain percentage of each hour.
1099 4. Gap Analysis
1101 4.1. Naive application of IPv6
1103 IPv6 [RFC2460] has been designed to allocate addresses to all the
1104 nodes connected to the Internet. Nevertheless, the header overhead
1105 of at least 40 bytes introduced by the protocol is incompatible with
1106 LPWAN constraints. If IPv6 with no further optimization were used,
1107 several LPWAN frames could be needed just to carry the IP header.
1108 Another problem arises from IPv6 MTU requirements, which require the
1109 layer below to support at least 1280 byte packets [RFC2460].
1111 IPv6 has a configuration protocol - neighbor discovery protocol,
1112 (NDP) [RFC4861]). For a node to learn network parameters NDP
1113 generates regular traffic with a relatively large message size that
1114 does not fit LPWAN constraints.
1116 In some LPWAN technologies, layer two multicast is not supported. In
1117 that case, if the network topology is a star, the solution and
1118 considerations of section 3.2.5 of [RFC7668] may be applied.
1120 Other key protocols such as DHCPv6 [RFC3315], IPsec [RFC4301] and TLS
1121 [RFC5246] have similarly problematic properties in this context.
1122 Each of those require relatively frequent round-trips between the
1123 host and some other host on the network. In the case of
1124 cryptographic protocols such as IPsec and TLS, in addition to the
1125 round-trips required for secure session establishment, cryptographic
1126 operations can require padding and addition of authenticators that
1127 are problematic when considering LPWAN lower layers.
1129 4.2. 6LoWPAN
1131 Several technologies that exhibit significant constraints in various
1132 dimensions have exploited the 6LoWPAN suite of specifications
1133 [RFC4944], [RFC6282], [RFC6775] to support IPv6 [I-D.hong-6lo-use-
1134 cases]. However, the constraints of LPWANs, often more extreme than
1135 those typical of technologies that have (re)used 6LoWPAN, constitute
1136 a challenge for the 6LoWPAN suite in order to enable IPv6 over LPWAN.
1137 LPWANs are characterized by device constraints (in terms of
1138 processing capacity, memory, and energy availability), and specially,
1139 link constraints, such as:
1141 o very low layer two payload size (from ~10 to ~100 bytes),
1143 o very low bit rate (from ~10 bit/s to ~100 kbit/s), and
1145 o in some specific technologies, further message rate constraints
1146 (e.g. between ~0.1 message/minute and ~1 message/minute) due to
1147 regional regulations that limit the duty cycle.
1149 4.2.1. Header Compression
1151 6LoWPAN header compression reduces IPv6 (and UDP) header overhead by
1152 eliding header fields when they can be derived from the link layer,
1153 and by assuming that some of the header fields will frequently carry
1154 expected values. 6LoWPAN provides both stateless and stateful header
1155 compression. In the latter, all nodes of a 6LoWPAN are assumed to
1156 share compression context. In the best case, the IPv6 header for
1157 link-local communication can be reduced to only 2 bytes. For global
1158 communication, the IPv6 header may be compressed down to 3 bytes in
1159 the most extreme case. However, in more practical situations, the
1160 smallest IPv6 header size may be 11 bytes (one address prefix
1161 compressed) or 19 bytes (both source and destination prefixes
1162 compressed). These headers are large considering the link layer
1163 payload size of LPWAN technologies, and in some cases are even bigger
1164 than the LPWAN PDUs. 6LoWPAN has been initially designed for IEEE
1165 802.15.4 networks with a frame size up to 127 bytes and a throughput
1166 of up to 250 kb/s, which may or may not be duty-cycled.
1168 4.2.2. Address Autoconfiguration
1170 Traditionally, Interface Identifiers (IIDs) have been derived from
1171 link layer identifiers [RFC4944] . This allows optimizations such as
1172 header compression. Nevertheless, recent guidance has given advice
1173 on the fact that, due to privacy concerns, 6LoWPAN devices should not
1174 be configured to embed their link layer addresses in the IID by
1175 default.
1177 4.2.3. Fragmentation
1179 As stated above, IPv6 requires the layer below to support an MTU of
1180 1280 bytes [RFC2460]. Therefore, given the low maximum payload size
1181 of LPWAN technologies, fragmentation is needed.
1183 If a layer of an LPWAN technology supports fragmentation, proper
1184 analysis has to be carried out to decide whether the fragmentation
1185 functionality provided by the lower layer or fragmentation at the
1186 adaptation layer should be used. Otherwise, fragmentation
1187 functionality shall be used at the adaptation layer.
1189 6LoWPAN defined a fragmentation mechanism and a fragmentation header
1190 to support the transmission of IPv6 packets over IEEE 802.15.4
1191 networks [RFC4944]. While the 6LoWPAN fragmentation header is
1192 appropriate for IEEE 802.15.4-2003 (which has a frame payload size of
1193 81-102 bytes), it is not suitable for several LPWAN technologies,
1194 many of which have a maximum payload size that is one order of
1195 magnitude below that of IEEE 802.15.4-2003. The overhead of the
1196 6LoWPAN fragmentation header is high, considering the reduced payload
1197 size of LPWAN technologies and the limited energy availability of the
1198 devices using such technologies. Furthermore, its datagram offset
1199 field is expressed in increments of eight octets. In some LPWAN
1200 technologies, the 6LoWPAN fragmentation header plus eight octets from
1201 the original datagram exceeds the available space in the layer two
1202 payload. In addition, the MTU in the LPWAN networks could be
1203 variable which implies a variable fragmentation solution.
1205 4.2.4. Neighbor Discovery
1207 6LoWPAN Neighbor Discovery [RFC6775] defined optimizations to IPv6
1208 Neighbor Discovery [RFC4861], in order to adapt functionality of the
1209 latter for networks of devices using IEEE 802.15.4 or similar
1210 technologies. The optimizations comprise host-initiated interactions
1211 to allow for sleeping hosts, replacement of multicast-based address
1212 resolution for hosts by an address registration mechanism, multihop
1213 extensions for prefix distribution and duplicate address detection
1214 (note that these are not needed in a star topology network), and
1215 support for 6LoWPAN header compression.
1217 6LoWPAN Neighbor Discovery may be used in not so severely constrained
1218 LPWAN networks. The relative overhead incurred will depend on the
1219 LPWAN technology used (and on its configuration, if appropriate). In
1220 certain LPWAN setups (with a maximum payload size above ~60 bytes,
1221 and duty-cycle-free or equivalent operation), an RS/RA/NS/NA exchange
1222 may be completed in a few seconds, without incurring packet
1223 fragmentation.
1225 In other LPWANs (with a maximum payload size of ~10 bytes, and a
1226 message rate of ~0.1 message/minute), the same exchange may take
1227 hours or even days, leading to severe fragmentation and consuming a
1228 significant amount of the available network resources. 6LoWPAN
1229 Neighbor Discovery behavior may be tuned through the use of
1230 appropriate values for the default Router Lifetime, the Valid
1231 Lifetime in the PIOs, and the Valid Lifetime in the 6CO, as well as
1232 the address Registration Lifetime. However, for the latter LPWANs
1233 mentioned above, 6LoWPAN Neighbor Discovery is not suitable.
1235 4.3. 6lo
1237 The 6lo WG has been reusing and adapting 6LoWPAN to enable IPv6
1238 support over link layer technologies such as Bluetooth Low Energy
1239 (BTLE), ITU-T G.9959, DECT-ULE, MS/TP-RS485, NFC IEEE 802.11ah. (See
1240 for details.) These technologies are
1241 similar in several aspects to IEEE 802.15.4, which was the original
1242 6LoWPAN target technology.
1244 6lo has mostly used the subset of 6LoWPAN techniques best suited for
1245 each lower layer technology, and has provided additional
1246 optimizations for technologies where the star topology is used, such
1247 as BTLE or DECT-ULE.
1249 The main constraint in these networks comes from the nature of the
1250 devices (constrained devices), whereas in LPWANs it is the network
1251 itself that imposes the most stringent constraints.
1253 4.4. 6tisch
1255 The 6tisch solution is dedicated to mesh networks that operate using
1256 802.15.4e MAC with a deterministic slotted channel. The time slot
1257 channel (TSCH) can help to reduce collisions and to enable a better
1258 balance over the channels. It improves the battery life by avoiding
1259 the idle listening time for the return channel.
1261 A key element of 6tisch is the use of synchronization to enable
1262 determinism. TSCH and 6TiSCH may provide a standard scheduling
1263 function. The LPWAN networks probably will not support
1264 synchronization like the one used in 6tisch.
1266 4.5. RoHC
1268 Robust header compression (RoHC) is a header compression mechanism
1269 [RFC3095] developed for multimedia flows in a point to point channel.
1270 RoHC uses 3 levels of compression, each level having its own header
1271 format. In the first level, RoHC sends 52 bytes of header, in the
1272 second level the header could be from 34 to 15 bytes and in the third
1273 level header size could be from 7 to 2 bytes. The level of
1274 compression is managed by a sequence number, which varies in size
1275 from 2 bytes to 4 bits in the minimal compression. SN compression is
1276 done with an algorithm called W-LSB (Window- Least Significant Bits).
1277 This window has a 4-bit size representing 15 packets, so every 15
1278 packets RoHC needs to slide the window in order to receive the
1279 correct sequence number, and sliding the window implies a reduction
1280 of the level of compression. When packets are lost or errored, the
1281 decompressor loses context and drops packets until a bigger header is
1282 sent with more complete information. To estimate the performance of
1283 RoHC, an average header size is used. This average depends on the
1284 transmission conditions, but most of the time is between 3 and 4
1285 bytes.
1287 RoHC has not been adapted specifically to the constrained hosts and
1288 networks of LPWANs: it does not take into account energy limitations
1289 nor the transmission rate, and RoHC context is synchronised during
1290 transmission, which does not allow better compression.
1292 4.6. ROLL
1294 Most technologies considered by the lpwan WG are based on a star
1295 topology, which eliminates the need for routing at that layer.
1296 Future work may address additional use-cases that may require
1297 adaptation of existing routing protocols or the definition of new
1298 ones. As of the time of writing, work similar to that done in the
1299 ROLL WG and other routing protocols are out of scope of the LPWAN WG.
1301 4.7. CoAP
1303 CoAP [RFC7252] provides a RESTful framework for applications intended
1304 to run on constrained IP networks. It may be necessary to adapt CoAP
1305 or related protocols to take into account for the extreme duty cycles
1306 and the potentially extremely limited throughput of LPWANs.
1308 For example, some of the timers in CoAP may need to be redefined.
1309 Taking into account CoAP acknowledgments may allow the reduction of
1310 L2 acknowledgments. On the other hand, the current work in progress
1311 in the CoRE WG where the COMI/CoOL network management interface
1312 which, uses Structured Identifiers (SID) to reduce payload size over
1313 CoAP may prove to be a good solution for the LPWAN technologies. The
1314 overhead is reduced by adding a dictionary which matches a URI to a
1315 small identifier and a compact mapping of the YANG model into the
1316 CBOR binary representation.
1318 4.8. Mobility
1320 LPWANs nodes can be mobile. However, LPWAN mobility is different
1321 from the one specified for Mobile IP. LPWAN implies sporadic traffic
1322 and will rarely be used for high-frequency, real-time communications.
1323 The applications do not generate a flow, they need to save energy and
1324 most of the time the node will be down.
1326 In addition, LPWAN mobility may mostly apply to groups of devices,
1327 that represent a network in which case mobility is more a concern for
1328 the gateway than the devices. NEMO [RFC3963] Mobility solutions may
1329 be used in the case where some end-devices belonging to the same
1330 network gateway move from one point to another such that they are not
1331 aware of being mobile.
1333 4.9. DNS and LPWAN
1335 The Domain Name System (DNS) DNS [RFC1035], enables applications to
1336 name things with a globally resolvable name. Many protocols use the
1337 DNS to identify hosts, for example applications using CoAP.
1339 The DNS query/answer protocol as a pre-cursor to other communication
1340 within the time-to-live (TTL) of a DNS answer is clearly problematic
1341 in an LPWAN, say where only one round-trip per hour can be used, and
1342 with a TTL that is less than 3600. It is currently unclear whether
1343 and how DNS-like functionality might be provided in LPWANs.
1345 5. Security Considerations
1347 Most LPWAN technologies integrate some authentication or encryption
1348 mechanisms that were defined outside the IETF. The working group may
1349 need to do work to integrate these mechanisms to unify management. A
1350 standardized Authentication, Accounting, and Authorization (AAA)
1351 infrastructure [RFC2904] may offer a scalable solution for some of
1352 the security and management issues for LPWANs. AAA offers
1353 centralized management that may be of use in LPWANs, for example
1354 [I-D.garcia-dime-diameter-lorawan] and
1355 [I-D.garcia-radext-radius-lorawan] suggest possible security
1356 processes for a LoRaWAN network. Similar mechanisms may be useful to
1357 explore for other LPWAN technologies.
1359 Some applications using LPWANs may raise few or no privacy
1360 considerations. For example, temperature sensors in a large office
1361 building may not raise privacy issues. However, the same sensors, if
1362 deployed in a home environment and especially if triggered due to
1363 human presence, can raise significant privacy issues - if an end-
1364 device emits (an encrypted) packet every time someone enters a room
1365 in a home, then that traffic is privacy sensitive. And the more that
1366 the existence of that traffic is visible to network entities, the
1367 more privacy sensitivities arise. At this point, it is not clear
1368 whether there are workable mitigations for problems like this - in a
1369 more typical network, one would consider defining padding mechanisms
1370 and allowing for cover traffic. In some LPWANs, those mechanisms may
1371 not be feasible. Nonetheless, the privacy challenges do exist and
1372 can be real and so some solutions will be needed. Note that many
1373 aspects of solutions in this space may not be visible in IETF
1374 specifications, but can be e.g. implementation or deployment
1375 specific.
1377 Another challenge for LPWANs will be how to handle key management and
1378 associated protocols. In a more traditional network (e.g. the web),
1379 servers can "staple" OCSP responses in order to allow browsers to
1380 check revocation status for presented certificates. [RFC6961] While
1381 the stapling approach is likely something that would help in an
1382 LPWAN, as it avoids an RTT, certificates and OCSP responses are bulky
1383 items and will prove challenging to handle in LPWANs with bounded
1384 bandwidth.
1386 6. IANA Considerations
1388 There are no IANA considerations related to this memo.
1390 7. Contributors
1392 As stated above this document is mainly a collection of content
1393 developed by the full set of contributors listed below. The main
1394 input documents and their authors were:
1396 o Text for Section 2.1 was provided by Alper Yegin and Stephen
1397 Farrell in [I-D.farrell-lpwan-lora-overview].
1399 o Text for Section 2.2 was provided by Antti Ratilainen in
1400 [I-D.ratilainen-lpwan-nb-iot].
1402 o Text for Section 2.3 was provided by Juan Carlos Zuniga and Benoit
1403 Ponsard in [I-D.zuniga-lpwan-sigfox-system-description].
1405 o Text for Section 2.4 was provided via personal communication from
1406 Bob Heile (bheile@ieee.org) and was authored by Bob and Sum Chin
1407 Sean. There is no Internet draft for that at present.
1409 o Text for Section 4 was provided by Ana Minabiru, Carles Gomez,
1410 Laurent Toutain, Josep Paradells and Jon Crowcroft in
1411 [I-D.minaburo-lpwan-gap-analysis]. Additional text from that
1412 draft is also used elsewhere above.
1414 The full list of contributors are:
1416 Jon Crowcroft
1417 University of Cambridge
1418 JJ Thomson Avenue
1419 Cambridge, CB3 0FD
1420 United Kingdom
1422 Email: jon.crowcroft@cl.cam.ac.uk
1424 Carles Gomez
1425 UPC/i2CAT
1426 C/Esteve Terradas, 7
1427 Castelldefels 08860
1428 Spain
1430 Email: carlesgo@entel.upc.edu
1432 Bob Heile
1433 Wi-Sun Alliance
1434 11 Robert Toner Blvd, Suite 5-301
1435 North Attleboro, MA 02763
1436 USA
1438 Phone: +1-781-929-4832
1439 Email: bheile@ieee.org
1441 Ana Minaburo
1442 Acklio
1443 2bis rue de la Chataigneraie
1444 35510 Cesson-Sevigne Cedex
1445 France
1447 Email: ana@ackl.io
1449 Josep PAradells
1450 UPC/i2CAT
1451 C/Jordi Girona, 1-3
1452 Barcelona 08034
1453 Spain
1455 Email: josep.paradells@entel.upc.edu
1457 Benoit Ponsard
1458 SIGFOX
1459 425 rue Jean Rostand
1460 Labege 31670
1461 France
1463 Email: Benoit.Ponsard@sigfox.com
1464 URI: http://www.sigfox.com/
1466 Antti Ratilainen
1467 Ericsson
1468 Hirsalantie 11
1469 Jorvas 02420
1470 Finland
1472 Email: antti.ratilainen@ericsson.com
1474 Chin-Sean SUM
1475 Wi-Sun Alliance
1476 20, Science Park Rd
1477 Singapore 117674
1478 Phone: +65 6771 1011
1479 Email: sum@wi-sun.org
1481 Laurent Toutain
1482 Institut MINES TELECOM ; TELECOM Bretagne
1483 2 rue de la Chataigneraie
1484 CS 17607
1485 35576 Cesson-Sevigne Cedex
1486 France
1488 Email: Laurent.Toutain@telecom-bretagne.eu
1490 Alper Yegin
1491 Actility
1492 Paris, Paris
1493 FR
1495 Email: alper.yegin@actility.com
1497 Juan Carlos Zuniga
1498 SIGFOX
1499 425 rue Jean Rostand
1500 Labege 31670
1501 France
1503 Email: JuanCarlos.Zuniga@sigfox.com
1504 URI: http://www.sigfox.com/
1506 8. Acknowledgments
1508 Thanks to all those listed in Section 7 for the excellent text.
1509 Errors in the handling of that are solely the editor's fault.
1511 In addition to the contributors above, thanks are due to Arun
1512 (arun@acklio.com), Dan Garcia Carrillo, Paul Duffy, Jiazi Yi, for
1513 comments.
1515 [[Ed: If I omitted anyone, sorry and just let me know and I'll add
1516 you here.]]
1518 Alexander Pelov and Pascal Thubert were the LPWAN WG chairs while
1519 this document was developed.
1521 Stephen Farrell's work on this memo was supported by the Science
1522 Foundation Ireland funded CONNECT centre .
1524 9. Informative References
1526 [RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
1527 DOI 10.17487/RFC0768, August 1980,
1528 .
1530 [RFC1035] Mockapetris, P., "Domain names - implementation and
1531 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
1532 November 1987, .
1534 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
1535 (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460,
1536 December 1998, .
1538 [RFC2904] Vollbrecht, J., Calhoun, P., Farrell, S., Gommans, L.,
1539 Gross, G., de Bruijn, B., de Laat, C., Holdrege, M., and
1540 D. Spence, "AAA Authorization Framework", RFC 2904,
1541 DOI 10.17487/RFC2904, August 2000,
1542 .
1544 [RFC3095] Bormann, C., Burmeister, C., Degermark, M., Fukushima, H.,
1545 Hannu, H., Jonsson, L-E., Hakenberg, R., Koren, T., Le,
1546 K., Liu, Z., Martensson, A., Miyazaki, A., Svanbro, K.,
1547 Wiebke, T., Yoshimura, T., and H. Zheng, "RObust Header
1548 Compression (ROHC): Framework and four profiles: RTP, UDP,
1549 ESP, and uncompressed", RFC 3095, DOI 10.17487/RFC3095,
1550 July 2001, .
1552 [RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins,
1553 C., and M. Carney, "Dynamic Host Configuration Protocol
1554 for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July
1555 2003, .
1557 [RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P.
1558 Thubert, "Network Mobility (NEMO) Basic Support Protocol",
1559 RFC 3963, DOI 10.17487/RFC3963, January 2005,
1560 .
1562 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the
1563 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
1564 December 2005, .
1566 [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet
1567 Control Message Protocol (ICMPv6) for the Internet
1568 Protocol Version 6 (IPv6) Specification", RFC 4443,
1569 DOI 10.17487/RFC4443, March 2006,
1570 .
1572 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
1573 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
1574 DOI 10.17487/RFC4861, September 2007,
1575 .
1577 [RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
1578 "Transmission of IPv6 Packets over IEEE 802.15.4
1579 Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007,
1580 .
1582 [RFC5216] Simon, D., Aboba, B., and R. Hurst, "The EAP-TLS
1583 Authentication Protocol", RFC 5216, DOI 10.17487/RFC5216,
1584 March 2008, .
1586 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
1587 (TLS) Protocol Version 1.2", RFC 5246,
1588 DOI 10.17487/RFC5246, August 2008,
1589 .
1591 [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
1592 Housley, R., and W. Polk, "Internet X.509 Public Key
1593 Infrastructure Certificate and Certificate Revocation List
1594 (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
1595 .
1597 [RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
1598 Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
1599 DOI 10.17487/RFC6282, September 2011,
1600 .
1602 [RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
1603 Bormann, "Neighbor Discovery Optimization for IPv6 over
1604 Low-Power Wireless Personal Area Networks (6LoWPANs)",
1605 RFC 6775, DOI 10.17487/RFC6775, November 2012,
1606 .
1608 [RFC6961] Pettersen, Y., "The Transport Layer Security (TLS)
1609 Multiple Certificate Status Request Extension", RFC 6961,
1610 DOI 10.17487/RFC6961, June 2013,
1611 .
1613 [RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
1614 Application Protocol (CoAP)", RFC 7252,
1615 DOI 10.17487/RFC7252, June 2014,
1616 .
1618 [RFC7668] Nieminen, J., Savolainen, T., Isomaki, M., Patil, B.,
1619 Shelby, Z., and C. Gomez, "IPv6 over BLUETOOTH(R) Low
1620 Energy", RFC 7668, DOI 10.17487/RFC7668, October 2015,
1621 .
1623 [I-D.farrell-lpwan-lora-overview]
1624 Farrell, S. and A. Yegin, "LoRaWAN Overview", draft-
1625 farrell-lpwan-lora-overview-01 (work in progress), October
1626 2016.
1628 [I-D.minaburo-lpwan-gap-analysis]
1629 Minaburo, A., Gomez, C., Toutain, L., Paradells, J., and
1630 J. Crowcroft, "LPWAN Survey and GAP Analysis", draft-
1631 minaburo-lpwan-gap-analysis-02 (work in progress), October
1632 2016.
1634 [I-D.zuniga-lpwan-sigfox-system-description]
1635 Zuniga, J. and B. PONSARD, "SIGFOX System Description",
1636 draft-zuniga-lpwan-sigfox-system-description-02 (work in
1637 progress), March 2017.
1639 [I-D.ratilainen-lpwan-nb-iot]
1640 Ratilainen, A., "NB-IoT characteristics", draft-
1641 ratilainen-lpwan-nb-iot-00 (work in progress), July 2016.
1643 [I-D.garcia-dime-diameter-lorawan]
1644 Garcia, D., Lopez, R., Kandasamy, A., and A. Pelov,
1645 "LoRaWAN Authentication in Diameter", draft-garcia-dime-
1646 diameter-lorawan-00 (work in progress), May 2016.
1648 [I-D.garcia-radext-radius-lorawan]
1649 Garcia, D., Lopez, R., Kandasamy, A., and A. Pelov,
1650 "LoRaWAN Authentication in RADIUS", draft-garcia-radext-
1651 radius-lorawan-03 (work in progress), May 2017.
1653 [TGPP36300]
1654 3GPP, "TS 36.300 v13.4.0 Evolved Universal Terrestrial
1655 Radio Access (E-UTRA) and Evolved Universal Terrestrial
1656 Radio Access Network (E-UTRAN); Overall description; Stage
1657 2", 2016,
1658 .
1660 [TGPP36321]
1661 3GPP, "TS 36.321 v13.2.0 Evolved Universal Terrestrial
1662 Radio Access (E-UTRA); Medium Access Control (MAC)
1663 protocol specification", 2016.
1665 [TGPP36322]
1666 3GPP, "TS 36.322 v13.2.0 Evolved Universal Terrestrial
1667 Radio Access (E-UTRA); Radio Link Control (RLC) protocol
1668 specification", 2016.
1670 [TGPP36323]
1671 3GPP, "TS 36.323 v13.2.0 Evolved Universal Terrestrial
1672 Radio Access (E-UTRA); Packet Data Convergence Protocol
1673 (PDCP) specification (Not yet available)", 2016.
1675 [TGPP36331]
1676 3GPP, "TS 36.331 v13.2.0 Evolved Universal Terrestrial
1677 Radio Access (E-UTRA); Radio Resource Control (RRC);
1678 Protocol specification", 2016.
1680 [TGPP36201]
1681 3GPP, "TS 36.201 v13.2.0 - Evolved Universal Terrestrial
1682 Radio Access (E-UTRA); LTE physical layer; General
1683 description", 2016.
1685 [TGPP23720]
1686 3GPP, "TR 23.720 v13.0.0 - Study on architecture
1687 enhancements for Cellular Internet of Things", 2016.
1689 [TGPP33203]
1690 3GPP, "TS 33.203 v13.1.0 - 3G security; Access security
1691 for IP-based services", 2016.
1693 [etsi_ltn]
1694 "ETSI Technical Committee on EMC and Radio Spectrum
1695 Matters (ERM) TG28 Low Throughput Networks (LTN)",
1696 February 2015.
1698 [fcc_ref] "FCC CFR 47 Part 15.247 Telecommunication Radio Frequency
1699 Devices - Operation within the bands 902-928 MHz,
1700 2400-2483.5 MHz, and 5725-5850 MHz.", June 2016.
1702 [etsi_ref]
1703 "ETSI EN 300-220 (Parts 1 and 2): Electromagnetic
1704 compatibility and Radio spectrum Matters (ERM); Short
1705 Range Devices (SRD); Radio equipment to be used in the 25
1706 MHz to 1 000 MHz frequency range with power levels ranging
1707 up to 500 mW", May 2016.
1709 [arib_ref]
1710 "ARIB STD-T108 (Version 1.0): 920MHz-Band Telemeter,
1711 Telecontrol and data transmission radio equipment.",
1712 February 2012.
1714 [LoRaSpec]
1715 LoRa Alliance, "LoRaWAN Specification Version V1.0.2",
1716 July 2016, .
1720 [LoRaSpec1.0]
1721 LoRa Alliance, "LoRaWAN Specification Version V1.0", Jan
1722 2015, .
1725 [ANSI-4957-000]
1726 ANSI, TIA-4957.000, "Architecture Overview for the Smart
1727 Utility Network", May 2013, .
1730 [ANSI-4957-210]
1731 ANSI, TIA-4957.210, "Multi-Hop Delivery Specification of a
1732 Data Link Sub-Layer", May 2013, .
1735 [wisun-pressie1]
1736 Phil Beecher, Chair, Wi-SUN Alliance, "Wi-SUN Alliance
1737 Overview", March 2017, .
1741 [wisun-pressie2]
1742 Bob Heile, Director of Standards, Wi-SUN Alliance, "IETF97
1743 Wi-SUN Alliance Field Area Network (FAN) Overview",
1744 November 2016,
1745 .
1748 [IEEE-802-15-4]
1749 "IEEE Standard for Low-Rate Wireless Personal Area
1750 Networks (WPANs)", IEEE Standard 802.15.4, 2015,
1751 .
1754 [IEEE-802-15-9]
1755 "IEEE Recommended Practice for Transport of Key Management
1756 Protocol (KMP) Datagrams", IEEE Standard 802.15.9, 2016,
1757 .
1760 Appendix A. Changes
1762 A.1. From -00 to -01
1764 o WG have stated they want this to be an RFC.
1766 o WG clearly want to keep the RF details.
1768 o Various changes made to remove/resolve a number of editorial notes
1769 from -00 (in some cases as per suggestions from Ana Minaburo)
1771 o Merged PR's: #1...
1773 o Rejected PR's: #2 (change was made to .txt not .xml but was
1774 replicated manually by editor)
1776 o Github repo is at: https://github.com/sftcd/lpwan-ov
1778 A.2. From -01 to -02
1780 o WG seem to agree with editor suggestions in slides 13-24 of the
1781 presentation on this topic given at IETF98 (See:
1782 https://www.ietf.org/proceedings/98/slides/slides-98-lpwan-
1783 aggregated-slides-07.pdf)
1785 o Got new text wrt Wi-SUN via email from Paul Duffy and merged that
1786 in
1788 o Reflected list discussion wrt terminology and "end-device"
1790 o Merged PR's: #3...
1792 A.3. From -02 to -03
1794 o Editorial changes and typo fixes thanks to Fred Baker running
1795 something called Grammerly and sending me it's report.
1797 o Merged PR's: #4, #6, #7...
1799 o Editor did an editing pass on the lot.
1801 Author's Address
1803 Stephen Farrell (editor)
1804 Trinity College Dublin
1805 Dublin 2
1806 Ireland
1808 Phone: +353-1-896-2354
1809 Email: stephen.farrell@cs.tcd.ie